docstr: Prepare sequences and convert it to Counters.
          
docstr_tok: ["Prepare","sequences","and","convert","it","to","Counters","."]
code: def _get_counters(
      self, *sequences: Sequence[object]
  ) -> list[Counter]:
      """Prepare sequences and convert it to Counters."""
      # already Counters
      if all(isinstance(s, Counter) for s in sequences):
          return list(sequences)  # type: ignore[arg-type]
      return [Counter(s) for s in self._get_sequences(*sequences)]
  
imports: from __future__ import annotations
  from collections import Counter
  from contextlib import suppress
  from typing import Sequence, TypeVar
  from ..libraries import prototype
  from ..utils import find_ngrams
label_desc: Use image node_id 12 for calling the Base obj's underlying member method code with example usage: obj._get_counters() and returns: unknown, list